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<head>
<script type="text/javascript">
	
	
	//产生一个四位的验证码。
	function createCode(){
		var datas = ['A','B','何','敏','凡','江','1','9']; // 0-7  长度8
		var code = "";
		for(var i = 0 ; i<4; i++){
			//随机产生四个索引值
			var index =  Math.floor(Math.random()*datas.length); // random 0.0-1.0（不包括1.0）
			code+=datas[index];
		}	
		
		var spanNode = document.getElementById("code");
		spanNode.innerHTML = code;
		spanNode.style.fontSize ="24px";
		spanNode.style.color = "red";
		spanNode.style.backgroundColor="gray";
		spanNode.style.textDecoration = "line-through";
	}
	
function ready(){
	createCode();
}
	


</script>
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<title>无标题文档</title>
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<body onload="ready()">
	<span id="code"></span><a href="#" onclick="createCode()">看不清，换一个</a>
	
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